If you have atrial fibrillation, taking blood thinners can reduce your risk of stroke. But they do cause other side effects, including serious bleeding.

Atrial fibrillation (AFib) is a heart rhythm disorder that may increase your risk of stroke. With AFib, the upper two chambers of your heart beat irregularly. Blood may pool and collect, creating clots that can travel to your organs and brain.

Doctors often prescribe anticoagulants, or blood thinners, to thin the blood and prevent clots from forming.

Here’s what you need to know about long-term blood thinner use, any side effects you might experience, and what you may want to discuss with a doctor.

If you have AFib, anticoagulants may lower your stroke risk by up to 60%. Because AFib doesn’t have many symptoms, some people feel they don’t want or need to take blood thinners, especially if it means taking a drug for the rest of their lives.

While blood thinners don’t necessarily change how you feel on a day-to-day basis, they help protect you against stroke.

You may encounter several types of blood thinners as part of treatment for AFib. These may include:

  • Warfarin (Jantoven): Warfarin reduces your body’s ability to make vitamin K. Without vitamin K, the liver has trouble making blood clotting proteins. Doctors have traditionally prescribed warfarin for all people with AFib; however, its current recommended uses are limited to Afib patients with a mechanical replacement heart valve and patients with rheumatic mitral stenosis.
  • Direct oral anticoagulants (DOACs): Doctors recommend these medications for people with AFib unless the person has moderate to severe rheumatic mitral stenosis or a mechanical replacement heart valve. Drugs in this category may include:

Doctors use a set of guidelines to determine what kind of blood thinner may be best for you.

Some people shouldn’t take blood thinners. Be sure to tell a doctor if you have any of the following medical conditions in addition to AFib:

Blood thinners can cause side effects. These side effects may depend on the particular drug you’re taking. Talking with a doctor about possible side effects of your prescribed medications is best. Common side effects of blood thinning medications can include:

  • increased risk of bleeding
  • increased risk of bleeding significantly from small cuts
  • skin rashes
  • hair loss

Be sure to tell a doctor if you experience a long nosebleed or bleeding gums or see blood in your vomit or feces. Severe bruising may also need a doctor’s prompt attention.

Blood thinners increase your risk of bleeding, including significant bleeding.

To manage this risk, consider making a few lifestyle changes. You can do the following are things at home to reduce your chances of bleeding from everyday activities:

  • Toss any firm-bristle toothbrushes and switch to ones with soft bristles.
  • Use waxed floss instead of unwaxed, which may damage your gums and cause bleeding.
  • Try an electric razor to avoid nicks and cuts.
  • Use sharp objects, like scissors or knives, with extra care.
  • Talk with a doctor about participating in any activities that might increase your chance of falling or injury, like contact sports. These may also increase your risk of internal bleeding.

While taking blood thinners, you may require medical monitoring and regular blood tests.


If you’re taking warfarin for the long haul, your medical team will likely monitor you closely.

You may regularly visit the hospital or clinic to have a blood test called a prothrombin time test. This test measures how long it takes for your blood to clot. It’s often performed monthly until a doctor can determine the best dose for your body.

Having your blood checked is something you’ll likely need to do while you’re taking the drug. Some people don’t need to change their dose of medication very often. Others must have frequent blood tests and changes to their dose to avoid side effects and excess bleeding.

Your medical team may also need to check you before certain medical procedures that involve bleeding, like surgery.

You may notice that the color of your warfarin pill can look different from time to time. The color represents the dose, so you should keep an eye on it and ask a doctor if you have questions about seeing a different color in your bottle.


Shorter-acting blood thinners like direct oral anticoagulants (DOACs) don’t usually require frequent monitoring. A doctor can give you more guidelines for treatment and any changes in the dosage.


Warfarin may interact with other medications you’re taking. The foods you eat may also change warfarin’s effect on your body.

If taking this drug for an extended time, you’ll want to ask a doctor more about necessary changes to your diet. They may recommend keeping your diet relatively stable in general and eating a consistent amount of foods high in vitamin K.

These foods include green, leafy vegetables such as:

  • kale
  • collard greens
  • Swiss chard
  • mustard greens
  • turnip greens
  • parsley
  • spinach
  • endive

If you’re taking warfarin, you may also want to limit certain foods from your diet that might interact with the medication. Instead, try eating a variety of foods that are low in vitamin K, including:

  • carrots
  • cauliflower
  • cucumbers
  • peppers
  • potatoes
  • squash
  • tomatoes

You should also talk with a doctor about herbal or omega-3 supplements to see if any you take may interact with your blood thinner.

You may also need to avoid certain foods or drinks that can increase warfarin’s effect and your risk of bleeding. These may include:

  • cranberry juice
  • grapefruit juice
  • pomegranate juice


Several recently described food and drug interactions have been reported in patients taking DOACs. Proton pump inhibitors taken for acid reflux can increase the anticoagulant action of DOACs. The herbal supplement St. John’s Wort, turmeric, coumarin, and other herbal products have been shown to interfere with the effectiveness of select DOACs. Excess fiber consumption will lower circulating drug levels as well. Speak with your doctor to verify that you’re taking the correct blood thinner.

If you have concerns about taking blood thinners long-term, you may want to speak with a doctor.

It’s important to take your medication at the same time each day. If you miss a dose, contact a doctor to see how you should get back on track.

Some people who remember their missed dose close to when they normally take it may be able to take it a few hours late. Others may need to wait until the following day and double up their dose. A doctor can advise you on the best method for your situation.

Some people set alarms or use medication reminder apps to avoid missing doses and stay organized.

When it’s an emergency

Call 911 or your local emergency services immediately if you experience any of the following symptoms while on blood thinners:

  • a severe or unusual headache
  • confusion, weakness, or numbness
  • bleeding that won’t stop
  • vomiting blood or blood in your stool
  • a fall or injury to your head

These situations may be signs of either internal bleeding or could lead to extreme blood loss. Acting fast may save your life.

Antidote medications can stop the effects of warfarin and get your blood to clot in an emergency, but you’ll need to go to a hospital for treatment.

DOACs, except dabigatran (Pradaxa), don’t currently have a reversal option to stop the medication’s effects.

Was this helpful?

The following includes frequently asked questions about using blood thinners long-term.

How long can a person stay on blood thinners?

In many instances, doctors may recommend a person stay on blood thinners for the rest of their life. This reduces the risk of experiencing a stroke.

What damage can blood thinners do?

Blood thinners may cause side effects, including bleeding and bruising. Significant bleeding can be life threatening and requires emergency medical treatment.

What are the disadvantages of taking blood thinners?

Blood thinners may cause side effects like nausea, bleeding, skin rashes, hair loss, and low blood cell counts. They may also increase your risk of significant bleeding.

Can you ever get off of blood thinners?

If you’ve experienced a blood clot, doctors may recommend that you continue taking anticoagulant medications for the rest of your life. This can reduce your risk of blood clots and stroke.

Taking blood thinners can prevent blood clots and stroke.

Bleeding is the biggest risk with long-term blood thinner use.

Blood thinners may not make you feel better on a daily basis. Still, they’re one of the best measures you can take to protect yourself against stroke if you have AFib. If you have concerns about blood thinners and their long-term use, speak with a doctor about the risks versus benefits.